Population Biology Flashcards
The extinction process can be broken down into which 2 paradigms ?
Declining population paradigm & Small population paradigm
Describe the declining population paradigm
- Habitat destrution
- habiotat degradation
- Habitat fragmentation
- Over-hunting & live capture
Pollution - Invasive species
- Major dx outbreaks
Describe the small population paradigm
“the effets of smallness”
-> factors causing extinction under this:
- Environmental stochasticity
- Catastrophes
- Demographic stochasticity
- Genetic deterioration
Define environmental stochasticity:
random unpredictable variation in environmental factors such as temp and rainfall
Define demogrpahic stochasticity
Random unpredictable variation in sex ratios, and births ad death rates
Define Catastrophes:
extreme environemental events such as disease epidemics ro hurricanes
Define Genetic stochasticity
Inbreeding depression, loss of genetic diversity and the accumulation of deleterious mutations
What does stable age distribution demographic look like
an age pyramid with more births and young animals than old
Demographic stochasticity will reflect events due to chance alone aka:
- Births, Deaths, sexr ratio at birth
Does demographic stochasticity have a larger impact on larger or smaller populations?
smaller
Define genetic diversity
The variety of alleles & gnotypes present in the group under study
How is genetic diversity observed?
- Polymorphism
- Allelic diversity
- Average heterozygosity (expected & observed)
Allelic diversity & heterozygosity what is it?
- Different forms of an allele for a particule trait (A,b, c, d which become Ab, Bc, Cd and this is heterozygosity)
What is Expected heterozygosity also known as?
Gene Diversity
What is expected heterozygosity?
Proportion of animals int he population expected to be heterozygous if random breeding takes place
T/ F The ability of a population to evolve depends on allelic heterozygosity and the rate at which it does depends on expected heterozygosity
True